Directing plasma distribution in plasma-enhanced chemical vapor deposition

Abstract

Plasma-enhanced chemical vapor deposition (PECVD) devices enable the generation of a plasma in a plasma zone of a deposition chamber, which reacts with a surface of a substrate to form a deposited film in the fabrication of a semiconductor component. The plasma generator is often positioned over the center of the substrate, and the generated plasma often remains in the vicinity of the plasma generator, resulting in a thicker deposition near the center than at the edges of the substrate. Tighter process control is achievable by positioning one or more electromagnets in a periphery of the plasma zone and supplying power to generate a magnetic field, thereby inducing the charged plasma to achieve a more consistent distribution within the plasma zone and more uniform deposition on the substrate. Variations in the number, configuration, and powering of the electromagnets enable various redistributive effects on the plasma within the plasma zone.

What is claimed is: 
     
       1. A plasma control device, comprising:
 an injection assembly through which precursor is injected, the injection assembly comprising:
 an annular pumping liner surrounding a shower head and having a set of liner apertures penetrating an outer surface of the annular pumping liner through which the precursor is emitted into a plasma zone of a chemical vapor deposition (CVD) chamber in which the precursor is converted to plasma; 
 
 a first electromagnet within a periphery of the plasma zone; 
 a second electromagnet within the periphery of the plasma zone, wherein:
 the first electromagnet and the second electromagnet are positioned between the injection assembly and a substrate, and 
 the first electromagnet and the second electromagnet are not laterally co-planar with the substrate; and 
 
 an electromagnet controller configured to adjust power to the first electromagnet and the second electromagnet based upon a specified distribution of the plasma relative to the substrate. 
 
     
     
       2. The plasma control device of  claim 1 , wherein the first electromagnet comprises at least one of iron (Fe); cobalt (Co); or nickel (Ni). 
     
     
       3. The plasma control device of  claim 1 , wherein:
 the first electromagnet is positioned within the periphery of the plasma zone at a first electromagnet position; and 
 the second electromagnet is positioned within the periphery of the plasma zone at a second electromagnet position that is approximately opposite the first electromagnet position. 
 
     
     
       4. The plasma control device of  claim 1 , wherein the first electromagnet and the second electromagnet are positioned within the periphery of the plasma zone to generate an approximately radially symmetric magnetic field. 
     
     
       5. The plasma control device of  claim 1 , wherein the first electromagnet and the second electromagnet are positioned within the periphery of the plasma zone to adjust a plasma distribution of the plasma in a selected region of the plasma zone. 
     
     
       6. The plasma control device of  claim 1 , wherein the first electromagnet and the second electromagnet are positioned within the periphery of the plasma zone to induce a directed flow of the plasma generated in the plasma zone. 
     
     
       7. The plasma control device of  claim 1 , wherein the electromagnet controller is operable to apply a selected power setting among at least two available power settings to the first electromagnet to alter a magnetic field generated by the first electromagnet. 
     
     
       8. The plasma control device of  claim 1 , wherein the electromagnet controller is operable to apply concurrently:
 a first selected power setting to the first electromagnet; and 
 a second selected power setting to the second electromagnet that is different from the first selected power setting. 
 
     
     
       9. The plasma control device of  claim 7 , wherein one of the at least two available power settings comprises an unpowered setting. 
     
     
       10. The plasma control device of  claim 7 , wherein:
 a first available power setting of the at least two available power settings induces, upon selection, a north/south polarity in the first electromagnet; and 
 a second available power setting of the at least two available power settings induces, upon selection, a south/north polarity in the first electromagnet. 
 
     
     
       11. A chemical vapor deposition (CVD) device, comprising:
 a CVD chamber comprising:
 a plasma zone, and 
 an injection assembly, comprising:
 an annular pumping liner surrounding a shower head and having a set of liner apertures penetrating an outer surface of the annular pumping liner through which a precursor is emitted into the plasma zone; 
 
 
 a precursor source connectable with the injection assembly and storing the precursor; 
 a plasma generator configured to generate a plasma from the precursor in the plasma zone; 
 at least one electromagnet positioned at a fixed location within a periphery of the plasma zone; and 
 an electromagnet controller configured to adjust power to the at least one electromagnet based upon a specified distribution of the plasma relative to a substrate. 
 
     
     
       12. The CVD device of  claim 11 , wherein the at least one electromagnet comprises a set of at least three electromagnets positioned radially around the plasma zone. 
     
     
       13. The CVD device of  claim 11 , wherein the at least one electromagnet comprises at least one electromagnet pair comprising:
 a first electromagnet positioned within the periphery of the plasma zone at a first electromagnet position; and 
 a second electromagnet positioned within the periphery of the plasma zone at a second electromagnet position that is approximately opposite the first electromagnet position. 
 
     
     
       14. The CVD device of  claim 13 , wherein:
 the first electromagnet and the second electromagnet are positioned between the injection assembly and the substrate, and 
 the first electromagnet and the second electromagnet are not co-planar with the substrate. 
 
     
     
       15. The CVD device of  claim 11 , wherein the electromagnet controller is operable to apply a selected power setting among at least two available power settings to the at least one electromagnet to alter an magnetic field generated by the at least one electromagnet. 
     
     
       16. The CVD device of  claim 11 , wherein the electromagnet controller is operable to apply concurrently:
 a first selected power setting to a first electromagnet; and 
 a second selected power setting to a second electromagnet that is different from the first selected power setting. 
 
     
     
       17. The CVD device of  claim 15 , wherein:
 a first available power setting of the at least two available power settings induces, upon selection, a north/south polarity in the at least one electromagnet; and 
 a second available power setting of the at least two available power settings induces, upon selection, a south/north polarity in the at least one electromagnet. 
 
     
     
       18. A chemical vapor deposition (CVD) device for applying plasma during formation of a semiconductor device on a substrate, comprising:
 a CVD chamber comprising:
 a plasma zone, and 
 an injection assembly, comprising:
 an annular pumping liner surrounding a shower head and having a set of liner apertures penetrating an outer surface of the annular pumping liner through which a precursor is emitted into the plasma zone; 
 
 
 a precursor source connectable with the CVD chamber and storing the precursor; 
 a plasma generator configured to generate the plasma from the precursor; and 
 an electromagnet positioned at a fixed location and configured to adjust an electromagnetic field based upon a specified distribution of the plasma relative to the substrate to steer the plasma relative to the substrate, wherein a bottom surface of the electromagnet is above a top surface of the substrate. 
 
     
     
       19. The CVD device of  claim 18 , comprising an electromagnet controller configured to provide power to the electromagnet. 
     
     
       20. The CVD device of  claim 18 , comprising:
 a second electromagnet configured to steer the plasma relative to the substrate; and 
 an electromagnet controller configured to adjust power to the electromagnet and the second electromagnet based upon the specified distribution of the plasma relative to the substrate.